• The Journal of Engineering Geology
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• v.24 no.4
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• pp.501-510
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• 2014

Volcanic eruptions alone may lead to serious natural disasters, but the associated release of water from a caldera lake may be equally damaging. There is both historical and geological evidence of the past eruptions of Mt. Baekdusan, and the volcano, which has not erupted for over 100 years, has recently shown signs of reawakening. Action is required if we are to limit the social, political, cultural, and economic damage of any future eruption. This study aims to identify the area that would be inundated following a volcanic flood from the Cheon-Ji caldera lake that lies within Mt. Baekdusan. A scenario-based numerical analysis was performed to generate a flood hydrograph, and the parameters required were selected following a consideration of historical records from other volcanoes. The amount of water at the outer rim as a function of time was used as an upper boundary condition for the downstream routing process for a period of 10 days. Data from the USGS were used to generate a DEM with a resolution of 100 m, and remotely sensed satellite data from the moderate-resolution imaging spectroradiometer (MODIS) were used to show land cover and use. The simulation was generated using the software FLO-2D and was superposed on the remotely sensed map. The results show that the inundation area would cover about 80% of the urban area near Erdaobaihezhen assuming a 10 m/hr collapse rate, and 98% of the area would be flooded assuming a 100 m/hr collapse rate.

• Journal of the Korean Ceramic Society
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• v.11 no.2
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• pp.3-10
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• 1974

For the manufacture of the silver-yellow glass, silver nitrate was used as a colorant in the base glass of $K_2O$-CaO-$SiO_2$ system. The latter in which the optimum condition was revealed showing beautiful yellow color had been selected among others after the preparatory studies to choose base glass. Other base glass systems considered were $Na_2O$-CaO-$SiO_2$, $R_2O$-PbO-$SiO_2$ and $R_2O$-PbO-BaO-$SiO_2$. The color developed on the specimen in various conditions was examined, using spectorphotometer, in term of the changes in absorbance with wavelength in the visible range. Experimental variables were the amount of the colorant and the additives, reheating temperature and time. The additives such as ZnO, BaO, $B_2O_3$ and $As_2O_3$ were added to increase the coloring action. It was observed that as the amount of silver increased in the base glass the absorbance around $410{\mu}m$ showed the increasing tendency, but the width of absorption curve was wider. Hence, the optimum amount of silver appeared to be 0.11~0.12%. It was found that ZnO was effective additive when present about 0.1%, while $As_2O_3$ ineffective rather retarding the coloration. Borax and $BaCO_3$ were proved effective when contained separately, but appeared ineffective when coexisted. Proper reheating temperature and time was ranged 550~$580^{\circ}C$ and 50~60 minutes. The higher the reheating temperature and the longer the reheating time, the absorbance was increased, while the width of absorption curve was wider. The colored glass prepared in the present experimental condition was found to have good water-resistance for the decorative purpose.

• The Korean Journal of Food And Nutrition
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• v.30 no.6
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• pp.1222-1228
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• 2017

In the current study, we investigated the inhibitory activity of water soluble ${\beta}-glucan$ from oat (Avena sativa) against various digestive enzymes such as ${\alpha}-glucosidase$, sucrase, maltase and glucoamylase. Inhibition of these enzymes involved in the absorption of disaccharide can significantly decrease the post-prandial increase of blood glucose level after a mixed carbohydrate diet. The ${\beta}-glucan$ had the highest documented rate of small intestinal sucrase inhibitory activity (2.83 mg/mL, $IC_{50}$) relevant for potentially managing post-prandial hyperglycemia. Furthermore, we evaluated the effects of ${\beta}-glucan$ on the level of post-prandial blood glucose in animal model. The post-prandial blood glucose levels were tested two hours after sucrose/starch administration, with and without ${\beta}-glucan$ (100, and 500 mg/kg-body weight). The maximum blood glucose levels (Cmax) of ${\beta}-glucan$ administration group were decreased by about 23% (from $219.06{\pm}27.82$ to $190.44{\pm}13.18$, p<0.05) and 10% (from $182.44{\pm}13.77$ to $165.64{\pm}10.59$, p<0.01) in starch and sucrose loading test, respectively, when compared to control in pharmacodynamics study. The ${\beta}-Glucan$ administration significantly lowered the mean, maximum, and minimum level of post-prandial blood glucose at 30 min after meal. In view of the foregoing, it is felt that our findings suggest that ${\beta}-glucan$ from oat serves to reduce post-prandial blood glucose rise secondary to slower absorption of glucose in the small intestine, via carbohydrate hydrolyzing enzymes inhibition.

• Journal of the Korea Computer Industry Society
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• v.8 no.2
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• pp.107-112
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• 2007

Laser wave length can have evaporation effect by absorption because outer skin or tissue of focus is consisted of water almost though absorption of water occurs more than 90% almost in formation thickness of very thin floor. Can operate outer skin, steam by floor and correct incision of formation is available. Suture surgical operation is available to vein or lymph system and surgical operation region can dry and see as eye and radish bleeding surgical operation is available. Specially, stability of tube both end output about pulse by weight very, this research can cause various curative effect because can reduce bulk and control easily current wave style of medical laser using electric power conversion device of high frequency way. If introduce ZVS (Zero Voltage Switching) or ZVZCS (Zero Voltage and Zero Current Switching), is more profitable because can reduce switching damage. Because electric power department of proposed medical laser can do stable soft-switching in wide subordinate extent introducing ZVZCS technique by the first help and control department composes microcontroller, output current waveform user have free form make Result that experiment because design and manufacture, brought result that improve of 20% than existing equipment, and will be bought to get into superior result if supplement as systematic late.

• Korean Journal of Weed Science
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• v.31 no.2
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• pp.212-219
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• 2011

The water dispersible granule flupoxam showed over 95% of weeding effect on the annual weeds of Poaceae such as Poa annua L., Digitaria ciliaris (Rets.) Koel and broad-leaf weeds. Efficacy of treatment had been lasted over 120 days in the $2kg\;ha^{-1}$ when it was treated from March to April while lasted over 180 days when it was treated from September to October. Because the flupoxam has a high soil absorptivity, a perfected herbicide layer is formed. This results in perfect weeding effect regardless of the presence or absence of thatch. Because the flupoxam has a different mechanism of action from the conventional herbicides such as dinitroanilines, pyridines, and carbamates, it is very effective with the alternative spray. Phytotoxicity symptoms was not observed and/or produced antocyan in new leaves in the landscape trees around the lawngrass by flupoxam treatment.

• Journal of Physiology & Pathology in Korean Medicine
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• v.34 no.1
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• pp.24-29
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• 2020

In this study, we investigated the inhibition effects of mixtures of Atractylodes macrocephala (AM) and Amomum villosum (AV) water extracts on adipocyte differentiation. Treatment with mixtures of AM and AV extracts in a ratio of 3:1 for 24 and 48 hours did not show any cytotoxicity in OP9 cells. Mixtures of AM(3) and AV(1) extracts inhibited adipocyte differentiation, expression of peroxisome proliferator-activated receptor gamma (PPARγ) and CCAT/enhancer-binding protein alpha (C/EBPα), the major transcription factors of differentiation. It also inhibited the expression of lipoprotein lipase (LPL), adipocyte protein 2 (aP2), which are PPARγ-target genes in adipocyte. We also checked the inhibition effects on cell proliferation during the early stage of differentiation by treatment with mixtures of AM(3) and AV(1) extracts. It markedly inhibited adipocyte proliferation after 48 hours, and also the phosphorylation of ERK1/2 and Akt after 10 min or 3 hour. These results identify a possible mechanism of action of mixtures of AM(3) and AV(1) extracts, suggesting that the mixtures of AM(3) and AV(1) extracts-induced inhibition of ERK and Akt phosphorylation suppresses adipogenesis by inhibiting other signaling cascades that include PPARγ and C/EBPα during the process of OP9 adipocyte differentiation.

• Corrosion Science and Technology
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• v.19 no.2
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• pp.82-88
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• 2020

This work examined the corrosion protection performance of benzoate loaded hydrotalcite/graphene oxide (HT/GO-BZ) for carbon steel. HT/GO-BZ was fabricated by the co-precipitation method and characterized by infrared spectroscopy, X-ray diffraction, and scanning electronic microscopy. The corrosion inhibition action of HT/GO-BZ on carbon steel in 0.1 M NaCl solution was evaluated by electrochemical measurements. The benzoate content in HT/GO-BZ was determined by UV-Vis spectroscopy. Subsequently, the effect of HT/GO-BZ on the corrosion resistance of the water-based epoxy coating was investigated by the salt spray test. The obtained results demonstrated the intercalation of benzoate and GO in the hydrotalcite structure. The benzoate content in HT/GO-BZ was about 16%. The polarization curves of the carbon steel electrode revealed anodic corrosion inhibition activity of HT/GO-BZ and the inhibition efficiency was about 95.2% at a concentration of 3g/L. The GO present in HT/GO-BZ enhanced the inhibition effect of HT-BZ. The presence of HT/GO-BZ improved the corrosion resistance of the waterborne epoxy coating.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.4
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• pp.698-703
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• 1994

In spore rec-assay using B. subtillus H17(rec) and M 45(rec) , the ethanol extract of buckwheat leaves showed antimutagenicity in condition of low concentrations, but its did comutagenicity in condition of high concentrations. In Ames test, the ethanol extract of buckwheat leaves reduced the mtabenicity of N-methyl-N' -nitro-N-nitrosoguaidine (MNNG), benzo (a) pyrene(B($\alpha$)P), 2-amino-fluorene(2AF), and 3-amino -1, 4-dime-thyl-5-H-pyrido(4, 3-b) indol(Trp-P-1) in Salmonella typhimurium TA98 and TA100. The ethanol extract was fractionated by hexane, ethylacetate, butanol and water. Among Them hexane fraction showed the highest inhibition rate on the mutagenicity of B($\alpha$)P, and so did chloroform fraction on the mutagenicity of MNNG in S. typhimurium Ta98 and TA100. To elucidate the antimutagenic mechanism of the ethanol extract, it was mixed and co-incubated with various metagens, S9 mix, and the bacteria with different experimental orders and different reaction times. The ethanol extract did not affect reversion rate of pre-mutated. S.typhimurium. However, when the ethanol extract was added to the mutagens before their interaction with S.typhimurium , it reduced the mutation rate to 152$\pm$12-273$\pm$18 colonies/plates in case of MNNG, and 135$\pm$13-195$\pm$10 colonies/ plates in case of B($\alpha$)P), showing strong desmutagenic activity.

• Journal of Pharmaceutical Investigation
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• v.27 no.4
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• pp.287-293
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• 1997

To make a stable o/w emulsion, the effects of egg lecithin as an emulsifier and polyvinylpyrrolidone (PVP) as an auxiliary emulsifier on the physical stability of emulsion were investigated. The oil-in-water emulsion system was manufactured by microfluidizer and evaluated the physical stability. Average particle size and size distribution of emulsion was measured by dynamic light scattering analyzer and interfacial tension was measured. From the interfacial tension tested, critical micelle concentration of the egg lecithin was 0.1 %w/v and optimal concentration for the preparation of emulsion was 1.0 %w/v. The mean particle size was about $0.2\;{\mu}m$ which was suitable for injections. The short-term accelerated stability studies were conducted by centrifugation, freeze-thaw method and shaking of the emulsion samples. The addition of PVP was caused the reduction in the particle size and improved the physical stability of emulsion. These results suggested that a mixed interfacial film comprising the egg lecithin and PVP was formed at the o/w interface and it was effective in preventing phase separation under thermic or mechanical stress. We used antineoplaston A10 (A10) as a model drug which is peptide and amino acid derivative having a action to the living organism against the development of neoplastic growth by a nonimmunological progress. It has a poor solubility in water and there may be a difficulty in formulation of A10. Emulsion formulation study about A10 was performed. Solubility of A10 in emulsion was about five times as high as that in water. From the results of solubility and partition coefficient, almost A10 molecules in o/w emulsion exist in the interface between oil and water.

• Korean Journal of Plant Resources
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• v.31 no.5
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• pp.423-432
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• 2018

This study was performed to develop a new natural antimicrobial materials by analyzing the effect of extracts obtained from Ten Lauraceae Species on the inhibitory activity against Propionibacterium acnes. The plant materials were collected from Wando and Jeju islands, and the antimicrobial activity of the crude extracts was examined by the agar diffusion method with different part (i.e., leaf and branch), solvents (i.e., distilled water, 80% ethanol, and 100% methanol) and at different ultrasonic extracting times (i.e., 15, 30, and 45 minutes). The control agents used were synthetic antimicrobials, methylparaben and phenoxyethanol, at concentrations of 0.4, 1, 2, and 4 mg/disc. Altogether, extracts of 10 species used in the study showed inhibitory activity, which confirmed their antimicrobial action against acnes. Among these, leaves of Laurus nobilis L. which was extracted in 80% ethanol for 45 min showed the largest clear zone (19.8 mm). Leaves of L. nobilis L., showing highest antimicrobial activities among 10 species, were successively reextracted with n-hexane, chloroform, ethylacetate and n-butanol. As a results, in all fractions except butanol, clear zone above 10 mm were formed. The ethyl acetate fraction showed the highest inhibitory activity (13.3 mm) and the inhibitory activity was significantly higher than that of crude extract (10.2 mm) and phenoxyethanol as a control (12.5 mm).